The present invention relates to an apparatus for securing or joining metal panel members to building structures for forming walls and dividers. More particularly, the invention relates to constructions which eliminate the need for certain sealants between wall panels members and which allow thermal expansion of the wall panel members to be absorbed by the connecting apparatus without causing warping or distortion of the wall panel members.
Walls have been constructed in the past using panels with wedges for securely trapping and holding the edges of panel members in place. French Pat. No. 1,381,143 to Kentzler illustrates one such system. In many of these prior panel attaching systems, the edges of the panel members are securely locked into position in such a manner that thermal expansion of the panel members produces warping or other distortion in the panel members.
U.S. Pat. No. 3,667,182 to Stemler illustrates one panel attaching device in which a flexible strip of rubber, plastic or other resilient material is used to hold two adjacent panels in position within a channel. In this way, the panels are allowed a certain degree of lateral movement relative to the framing as they expand, contract, or are subjected to changes in load thereon. U.S. Pat. No. 3,832,820 to Eggert illustrates a similar panel mounting device in which a channel has edges formed in the shape of a hook, panels to be positioned within the channel have a corresponding hook shaped portion, and a strip of resilient material having a circular cross section is wedged in the channel to hold the hooks in interlocking relation.
U.S. Pat. Nos. 4,344,267 and 4,452,029, both to Sukolics, illustrate a panel securing apparatus which allows for thermal expansion of the panel members. The apparatus comprises a channel member having sidewalls with integral semi-cylindrical locking portions adapted to engage similarly shaped portions on the edges of panels to be positioned within the channel. To hold and lock the panel edges within the channel, a rigid member having protrusions is inserted between the panel members.
Many of these panel securing systems are known as wet set systems because of their use of sealants such as silicone sealants to seal the gaps in exterior walls. In these systems, the sealant when exposed to the atmosphere, in some environments, collects dirt and allows it to spread across the panel faces rendering them aesthetically unappealing. To overcome this problem, it has been proposed to replace the "wet" sealant exposed to the atmosphere by a dry sealant.
Accordingly, it is an object of the present invention to provide a panel securing apparatus which does not require the use of an external wet sealant to close the gap between adjacent panels forming an exterior wall.
It is a further object of the present invention to provide a panel securing apparatus as above which also allows for thermal expansion and/or contraction of adjoining panel members.
It is yet another object of the present invention to provide a panel securing apparatus as above which permits the panel members to retain an aesthetically pleasing appearance.
These and other objects and advantages will become more apparent from the following description and drawings in which like reference numerals depict like elements.